<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>定义变量</title>
	<link rel="stylesheet" href="css/02.css">
</head>
<body>
	<div id="d1" class="itany">div1</div>
	<br>
	<div class="d1">div2</div>
	<br>
	<div class="c1 c2 c3 c4">div3</div>
</body>
</html>